We used the two demonstrations below to practice solving problems with forces acting an an angle where one or two values are unknown. This was our first real practice solving systems of equations, which we will be using to analyze two-body systems in the upcoming week. In the first demonstration, paper covered the spring scales in the top right and left which we uncovered after calculating what the values should be. In the second, there is an unknown amount of weight suspended on the left and right, inside each of the two boxes. I got this years ago from Aaron Debbink.
Randall Physics 